title: Real-time outdoor concealed-object detection with passive millimeter wave imaging.
abstract: Millimeter wave imaging is finding rapid adoption in security applications such as the detection of objects concealed under clothing. A passive imaging system can be realized as a stand-off type sensor that can operate in open spaces, both indoors and outdoors. In this paper, we address real-time outdoor concealed-object detection and segmentation with a radiometric imaging system operating in the W-band. The imaging system is equipped with a dielectric lens and a receiver array operating at around 94 GHz. Images are analyzed by multilevel segmentation to identify a concealed object. Each level of segmentation comprises vector quantization, expectation-maximization, and Bayesian decision making to cluster pixels on the basis of a Gaussian mixture model. In addition, we describe a faster process that adopts only vector quantization for the first level segmentation. Experiments confirm that the proposed methods provide fast and reliable detection and segmentation for a moving human subject carrying a concealed gun.
authors.affiliation: Division of Computer and Communication Engineering, Daegu University, Gyeongsan, Gyeongbuk 712-714, Korea 2SamsungThales, Yongin 449-885, Korea. yeom@daegu.ac.kr
authors.forename: Seokwon
authors.initials: S
authors.lastname: Yeom
authors.forename: Dong-Su
authors.initials: DS
authors.lastname: Lee
authors.forename: Jung-Young
authors.initials: JY
authors.lastname: Son
authors.forename: Min-Kyoo
authors.initials: MK
authors.lastname: Jung
authors.forename: YuShin
authors.initials: Y
authors.lastname: Jang
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Jung
authors.forename: Seok-Jae
authors.initials: SJ
authors.lastname: Lee
mesh_terms: D003199:Computer Systems; D004784:Environmental Monitoring / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D008872:Microwaves